Through the undisturbed samples and reconstituted samples for compression test, analyzed and got the characteristics of compression deformation and the influence law of structure properties on soft clay. The s-t curves deformation of reconstituted soil in small loads is the largest, as the load increases, tends gradually to horizontal line, but undisturbed soil deformation is the largest under the condition of a bigger load. Undisturbed soil due to structural exists, its s-lgt curves are divided into three categories according to load level. The e-lgp curve of soft clay is bounded by structure yield stress very clearly divided into two sections, but e-lgp curve of reconstituted soil is a straight line. Because structure of the reconstituted soil has been destroyed, its law of compression characteristics is comparative markedly. But due to the existence of undisturbed soil structural properties, near the structural yield stress, the compression parameters appear mutations. Research results show that influence of soft clay structural properties on its compression characteristics is not allowed to ignore.